will now be safer. Astonishing images out of arizona next. Take a look. A massive dust storm blanketing a major american city, phoenix. And clayton sandell has the latest on that. Reporter: Today, a wall of dust came stalking the phoenix area. Ra giant brown cloud knocking out electricity to thousands, delays flights at the airports and creates chaos. People caught in the blast, covering their mouths and noses. It's known as a haboob, a freak desert dust storm. It happens almost every summer in the southwest. Killing five people a year. A very, very dry dust and hits with the wind and it just gets pushed. Reporter: It went from open land to city terrain, it met its match. It starts to fall down and then the storm just falls apart. Reporter: As the haboob moves through, it's followed by rain and flash floods, turning much of the dust to mud. And still ahead here on "world news," it sounded so

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